Gen 3 Extruder Problem

1/ Running gen 3 electronics.
2/ Cannot get graphics to work in Repsnapper, so am using Skeinforge, which I am very happy with.
3/ Once Repsnapper is loaded and the axes are homed, all the steppers behave as expected.
4/ I have all the motors standing side by side on the table, as I want to make sure everything works perfectly before mounting into the machine.

After generating the gcode in skeinforge and loading it into Repsnapper, and having selected extruder 0, when I start the program it all seems to be going great. The x and y axes move to the start point and the extruder motor turns perfectly, but as soon as the program starts to create the part the x,y and z motors behave perfectly, but the extruder motor shudders and jerks and gets very hot.
I have got a lot of help from this forum so far and am hoping that someone has had similar issues with gen 3 kit and that they can pass on their solutions to me.

... seems your steprate for the extruder motor went to high when printing, so the motor stalls - try to reduce the speed ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks Viktor, thats makes perfect sense. I cant determine the exact spot in skeinforge settings that controls the extruder motor steps. Any ideas?

... should be a parameter like "E_steps_per_mm" in the firmware which adjust your extruding rate ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

What are your speed settings in Skeinforge?

My speed settings are as follows:
Format is tab separated speed settings.

Name                          	Value
WindowPosition	700+0
Open File for Speed	
Activate Speed:	True
Add Flow Rate:	True
Bridge Feed Rate Multiplier (ratio):	1.11
Bridge Flow Rate Multiplier (ratio):	1.0
Duty Cyle at Beginning (portion):	0.75
Duty Cyle at Ending (portion):	0.0
Feed Rate (mm/s):	32.0
Flow Rate Setting (float):	40.0
Orbital Feed Rate over Operating Feed Rate (ratio):	0.5
Perimeter Feed Rate over Operating Feed Rate (ratio):	0.8
Perimeter Flow Rate over Operating Flow Rate (ratio):	1.0
Travel Feed Rate (mm/s):	32.0

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Here is a comparison. What do you think?

Current settings
Activate Speed: True TRUE
Add Flow Rate: True TRUE
Bridge Feed Rate Multiplier (ratio): 1.11 1
Bridge Flow Rate Multiplier (ratio): 1.0 1
Duty Cyle at Beginning (portion): 0.75 1
Duty Cyle at Ending (portion): 0.0 0
Feed Rate (mm/s): 32.0 30
Flow Rate Setting (float): 40.0 30
Orbital Feed Rate over Operating Feed Rate (ratio): 0.5 0.5
Perimeter Feed Rate over Operating Feed Rate (ratio): 0.8 0.4
Perimeter Flow Rate over Operating Flow Rate (ratio): 1.0 0.4
Travel Feed Rate (mm/s): 32.0 50

Should be a good starting point.

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Got it!!!. I found that changing the settings in the speed page had little to no effect, but I went into the ramp page and changed the settings on all the flow related windows, and I now have an extruder motor that not only turns, but retracts when it should and best of all you can't fry an egg on it anymore!
Thanks again to all those who gave me a helping hand.

I have the exact same problem but cant seem to find the settings of which you speak... Still going with gen3 electronics.
Can someone please explain the solution?

I use RepSnapper, and settings in the "extruder" in the fiveD_GCode_Interpreter (what i got as firmware) is as follows:

/*!
Manages extruder functions to keep temps, speeds etc
at the set levels. Should be called only by manage_all_extruders(),
which should be called in all non-trivial loops.
o If temp is too low, don't start the motor
o Adjust the heater power to keep the temperature at the target
*/
void extruder::manage()
{
//make sure we know what our temp is.
int current_celsius = getTemperature();
byte newheat = 0;

//put the heater into high mode if we're not at our target.
if (current_celsius < target_celsius)
newheat = heater_high;
//put the heater on low if we're at our target.
else if (current_celsius < max_celsius)
newheat = heater_low;

// Only update heat if it changed
if (heater_current != newheat) {
heater_current = newheat;
analogWrite(heater_pin, heater_current);
}
}


#if 0
void extruder::setSpeed(float sp)
{
// DC motor?
if(step_en_pin < 0)
{
e_speed = (byte)sp;
if(e_speed > 0)
waitForTemperature();
analogWrite(motor_speed_pin, e_speed);
return;
}

// No - stepper
disableTimerInterrupt();

if(sp <= 1.0e-4)
{
disableStep();
e_speed = 0; // Just use this as a flag
return;
}
else
{
waitForTemperature();
enableStep();
e_speed = 1;
}

extrude_step_count = 0;

float milliseconds_per_step = 60000.0/(E_STEPS_PER_MM*sp);
long thousand_ticks_per_step = 4*(long)(milliseconds_per_step);
setupTimerInterrupt();
setTimer(thousand_ticks_per_step);
enableTimerInterrupt();
}

void extruder::interrupt()
{
if(!e_speed)
return;
extrude_step_count++;
if(extrude_step_count > 1000)
{
step();
extrude_step_count = 0;
}
}

#endif
#endif